Index: sys/arm/include/atomic-v6.h
===================================================================
--- sys/arm/include/atomic-v6.h
+++ sys/arm/include/atomic-v6.h
@@ -863,6 +863,7 @@
 {
 	int newv, oldv, result;
 
+	bit &= 0x1f;
 	__asm __volatile(
 	    "   mov     ip, #1					\n"
 	    "   lsl     ip, ip, %[bit]				\n"
@@ -907,6 +908,7 @@
 {
 	int newv, oldv, result;
 
+	bit &= 0x1f;
 	__asm __volatile(
 	    "   mov     ip, #1					\n"
 	    "   lsl     ip, ip, %[bit]				\n"
@@ -953,10 +955,8 @@
 
 	p32 = (volatile uint32_t *)p;
 	/* Assume little-endian */
-	if (v >= 32) {
-		v &= 0x1f;
+	if ((v & 0x20) != 0)
 		p32++;
-	}
 	return (atomic_testandset_32(p32, v));
 }